After I purchased my pickup truck, I brought a book on gasoline engines to avoid being ripped off at the service station. The first time I took the truck in for repairs, I smugly wrote down what the problem was and what needed to be fixed.
That night when I returned for the truck, I found this note attached to the windshield: “I fixed the problem in your truck, but in order for me to fix the problem you described, you’ll have to bring in the lawnmower. I suggest you go back a couple of chapters. My wife has the same book.”